Question about 45 cal. revolvers

[MikeS]

Hi All.

I have a question about 45 caliber revolvers. What size is the distance between the barrel, and the cylinder supposed to be? Or should I say, what is considered the 'normal' range? I have 4 45 caliber revolvers, 2 Rugers, a Smith & Wesson, and a Cimmaron that I've had re-barreled. Of them, the space between the cylinder & barrel (I don't know if there's a name for it) on the Rugers were the largest, at .007" The Smith & Wesson model 22-4 that I just bought is .006", and the custom re-barreled Cimmaron was the smallest at .003". The way I measured them was with a feeler gauge, and the size I'm listing is the largest one that would slip between the cylinder & barrel, with the next size up (the set is in .001" steps) not slipping between them. While I haven't shot the Smith yet, the other pistols shoot just fine, I'm just curious if there's a stated min & max sizes for the gap between barrel & cylinder, as there seems to be a variation between them. Also, will the size of the gap make a difference in how well the revolver will shoot cast boolits? Thanks!

[geargnasher]

I keep seeing the number of three to six thousandths tossed around for cylinder gap specs, the only one of mine I ever bothered to measure was my Open Top, and only then to verify correct barrel wedge setting. Check the Ruger again like you did using your feeler gauges, but with a dummy round or empty chambered in the firing position, might make a difference, might not. If I had the tools I'd be sorely tempted to rebarrel every Ruger I own so I could set the cylinder gap to minimum and do with a lot less forcing cone. But for working guns they shoot way better than I can anyway, so there doesn't seem to be much harm in a little slop unless you're target shooting.

FWIW,

Gear

[MikeS]

Gear: thanks. I thought that range was about right. Also, I did have a dummy in the chamber when I did the measurements. I guess I should also try with an empty cylinder to see if there's any change as you said.

When I got the Smith it had Herrett wooden target grips on it (put on by my gun dealer to replace the tacky plastic pearl grips that were on it), and I have fairly small hands, and the gun didn't fit in my hand right. I bought a set of Hogue rubber grips for it, and now it fits in my hand much better. This gun is basically replacing a JM625 that I had that was stolen, and while it's not a target pistol, and has fixed sights, I'm hoping it's almost as accurate as the 625 was. I found all my moon clips, now I just need to find my de-mooning tool that I had when I had the 625! I really like having a gun that's as strong as any other modern Smith & Wesson, but has the look of their older guns. This one is a copy of the Model of 1950, it has a 4" barrel, and a nickel plating that's a really high gloss, and just looks like it's a better job of fit & finish than some of the other newer Smiths I've seen.

While it was technically second hand, the original purchaser never fired it, and I think it sat in his safe since he bought it back in 2007, as the little bit of handling of it I've given in in the 3 or 4 days I've owned it has sort of broken it in a bit. The only thing he (or she) did with the gun was to change the original grips to a set of pearlized plastic grips that my dealer swapped out for the wooden Herrett grips, which I swapped out with the Hogue ones (I got the grips at a different store, so I still have the wooden ones).

After I got it, I did some searching on the web, and the only 22-4's I could find were blued, until I finally found a site that mentioned that it was also made in nickel, and came with rubber grips (that look just like the Hogues I put on it!) that had the S&W logo on it, and that they made very few of them, so it seems that the model I got is somewhat rare!

I love it when I get something like this, as because it was technically used I bought it for about half of what it was originally selling for, yet got a gun that is for all purposes a new gun! I don't fall into these kinds of deals too often, so I'm real happy when I do, and I'm sure my dealer didn't realize that the nickel gun is a rarity, otherwise she would have charged more for it! Sorry for rambling on about this new gun!

[Breadman03]

.004-.008 is listed as the proper barrel/cylinder gap for the Ruger GP100 in a manual produced by a retired gunsmith.

[contender1]

Generally, a .005 is a good place for most of them. Much tighter, and you can get binding. Much looser, and you'll have other issues.

[Larry Gibson]

.004-.008 is listed as the proper barrel/cylinder gap for the Ruger GP100 in a manual produced by a retired gunsmith.

That's a pretty good specification. Much tigher than .004 ong factory revolvers and the revolver can bind/jam up when heated during firing or when fouled. Custom barreled ones should have had the cylinder faced off to be perpendicular to the face of the barrel. Many factory revolvers are not the true. If the forcing cone is correct and the alignment correct between throats and barrel I've seen several revolvers with as much as .010 - .012 barrel/cylinder gap shoot quite well.

Larry Gibson

[Mal Paso]

That's a pretty good specification. Much tigher than .004 ong factory revolvers and the revolver can bind/jam up when heated during firing or when fouled. Custom barreled ones should have had the cylinder faced off to be perpendicular to the face of the barrel. Many factory revolvers are not the true. If the forcing cone is correct and the alignment correct between throats and barrel I've seen several revolvers with as much as .010 - .012 barrel/cylinder gap shoot quite well.

Larry Gibson

+1 Tighter than .004 and a chip of lead or grain of powder can tie up the cylinder making a second shot difficult. Been there.

[jameslovesjammie]

I thought that I read once that when you measure barrel to cylinder gap, you should do it at full lockup (hammer all the way back and dropped by trigger) holding back the trigger and measuring the gap with a feeler gauge. Do this every 2 chambers to check for inconsistancy in the face of the cylinder.

I don't remember where I read it, but it has worked for me!

[Bullwolf]

I used to set a gap between .004 and .005 with a feeler gauge on my Dan Wesson revolver when I changed barrels.

Much more than that and you run the risk of binding up the cylinder. I have seen that happen before with some really tight fitting revolvers.

I have shot gaps loose as .007 to .008 Given a choice I would rather have things on the tight side, rather than loose. Other than some excess blast coming from the gap however, things still functioned.

If I was going to purchase a used revolver, with a barrel to cylinder gap that was over .008, I would probably hold off on the purchase thinking it had been shot quite a bit, or was maybe abused. You could always shim it I suppose if the gap was excessive, and it bothered you.

- Bullwolf

[prs]

The Cimmeron is gonna be a little difficult if you shoot real gun powder in your frontier cartridge adventures. I like the way your roogers are set.

prs

[MikeS]

The Cimmeron is gonna be a little difficult if you shoot real gun powder in your frontier cartridge adventures. I like the way your roogers are set.

prs

Actually I had considered doing this, and in fact even have a mould you designed (or helped design, I'm not sure, the one for the ROA) that I've loaded into 45Colt cases to be fired either in the Cimmeron, or the Rugers (I also have a conversion cylinder for the ROA). I didn't check the fit of the conversion cylinder, the .007" was with the factory cylinder.

[fredj338]

I used to set a gap between .004 and .005 with a feeler gauge on my Dan Wesson revolver when I changed barrels.

Much more than that and you run the risk of binding up the cylinder. I have seen that happen before with some really tight fitting revolvers.

- Bullwolf

Same here. When the gap gets too big, the rev spits, a lot. Too small, it will bind wehn dirty or hot.

[Tatume]

My Freedom Arms M83 revolver (454 Casull) has a barrel/cylinder gap of about 0.001" and has never given a hint of binding. It also has a very tight relationship between the cylinder pin and cylinder, and this does get dirty and become stiff, after about 100 rounds. All it takes to restore free rotation is to slide the pin out, wipe it clean with a spot of WD40, and it's good for another 100 rounds. I have found that conventional oils absorb combustion byproducts and cause the cylinder to get stiff sooner, so WD40 is the best cleaner and lubricant. Each time I pull the pin I also put a spot of oil on the face of the bearing, as John Linebaugh claims this prolongs the life of the barrel/cylinder relationship. I don't know it this is true, but it doesn't hurt.

I also have many S&W and Ruger revolvers. In my experience, an even gap is much more important than the absolute width of the gap. I had a brand new S&W revolver that had a wider gap on one side than the other, and it spit like crazy on the wide side. Accuracy was also quite poor. S&W was very good about fixing the defect (they replaced the barrel), but it shouldn't have gotten out the door in the first place.

[Bullwolf]

My Freedom Arms M83 revolver (454 Casull) has a barrel/cylinder gap of about 0.001" and has never given a hint of binding. It also has a very tight relationship between the cylinder pin and cylinder, and this does get dirty and become stiff, after about 100 rounds. All it takes to restore free rotation is to slide the pin out, wipe it clean with a spot of WD40, and it's good for another 100 rounds.

Back in the 1990's A friend brought a brand new Freedom Arms Casull revolver over to my place to shoot a bit. It had a 10 inch barrel and was chambered in 50 Action Express, not 454 Casull.

We shot a couple of boxes of the old 50AE Samsom IMI factory JHP's through the gun, and the Casull bound up on us when it got dirty.

When I say bound up, I am not talking about bullet pull under recoil tying up the front of the cylinder. The cylinder gap was so tight on the Casull, that carbon fouling build up would make the cylinder really stiff, and eventually it didn't want to move anymore.

Anyways, it was easily fixed with a little cleaning and lube, but it surprised me just how tight the cylinder gap was on that gun. All I had to compare it with at the time were a few factory Smith and Wesson revolvers, an old Ruger Blackhawk, a Redhawk, and my Dan Wesson revolver. I recall measuring the gap on the Casull, with the a same feeler gauges I used to set the gap on my Dan Wesson revolver. The cylinder end gap was between .001 and .002 on the Casull, and it took my smallest feeler gauge. I assumed at the time that that was what was causing the gun to bind up. It could easily have been a dirty cylinder pin as well.

This incident was pretty much why I would set the barrel to cylinder end gap on my Dan Wesson revolver between .004 and .005.

Speaking of the Dan Wesson, I really did like the interchangeable barrel set up that the Dan Wesson revolvers used. I sure wish someone today made an affordable, modern revolver that used the same barrel nut system.

The factory must also crimp those 50AE J-word bullets a lot tighter than I can taper crimp a cast boolit in that caliber. (Maybe they use a roll crimp?) I have even pulled down some factory 50AE that seemed to use an adhesive, as well as a really serious crimp.

I took the extremely tight fitting cylinder gap on the Casull as a sign of quality and pride in workmanship, but perhaps it was just a tad bit too tight? This was also a brand new gun, and maybe it loosened up some after break in. Since this was not my revolver I don't really know how it behaved later, after many rounds had been fired through it.


- Bullwolf